Fabrication method and fabrication apparatus of head using near field light

1. A method of fabricating a head using near field light, the head comprising an air bearing surface that faces a surface of a recording medium and a near field optical element having a truncated pyramid including a top surface that faces the surface of the recording medium and a plurality of side surfaces, the method comprising: a step of forming on a surface of a substrate a first projection having the top surface and the plurality of side surfaces and corresponding to the truncated pyramid of the near field optical element, and a second projection for the air bearing surface; a step of forming a metal film on at least a first side surface of the plurality of side surfaces of the first projection; a step of providing at least a part of a sacrificial interconnect on anyone of the first projection and the second projection; a step of disposing on the surface of the substrate a conductive interconnect electrically connected to the sacrificial interconnect; a step of electrically connecting the conductive interconnect to an electrical resistance detecting unit; a step of arranging a flat polishing material so as to face the surface of the substrate; and a step of polishing the first projection, the second projection, and the sacrificial interconnect using the polishing material until a value of an electrical resistance of the sacrificial interconnect detected by the electrical resistance detecting unit reaches a predetermined value so that the top surface of the first projection has a predetermined size and is arranged on the same plane as that of the air bearing surface.

2. A method of fabricating a head using near field light according to claim 1 ; wherein the step of forming the metal film comprises: a step of depositing a sacrificial layer on at least a second side surface of the plurality of side surfaces of the first projection facing the first side surface and from a direction perpendicular to the second side surface; a step of depositing the metal film at least on the first side surface of the first projection; and a step of removing the sacrificial layer deposited on the second side surface of the first projection.

3. A method of fabricating a head using near field light according to claim 1 ; wherein in the polishing step, the metal film is polished together with the first projection, second projection and sacrificial interconnect until an end surface of the polished metal film is arranged on the same plane as the top surface of the first projection.

4. A method of fabricating a head using near field light according to claim 1 ; wherein the second projection comprises a floating projection having the air bearing surface; and wherein in the providing step, at least a part of the sacrificial interconnect is formed on a top surface of the second projection.

5. A method of fabricating a head using near field light according to claim 1 ; wherein the first projection has an element projection corresponding to the near field optical element and another projection different from the element projection; and wherein in the providing step, at least a part of the sacrificial interconnect is formed on a top surface of the another projection.

6. A method of fabricating a head using near field light according to claim 1 ; wherein the first projection has an element projection corresponding to the near field optical element and another projection different from the element projection; and wherein in the providing step, at least a part of the sacrificial interconnect is formed on the top surface of the element projection.

7. A method of manufacturing a near-field optical head, comprising: a step of forming on the surface of a substrate a first projection shaped in a quadrangular pyramid for providing a near-field optical element of the near-field optical head; a step of forming on a surface of a substrate a second projection shaped in a frustum of quadrangular pyramid for providing an air bearing surface of the near-field optical head; a step of forming a metal film on at least one surface of the first projection; a step of connecting the metal film with a resistance meter through a conduction wiring for detecting an electrical resistance of the metal film; and a step of polishing the first and second projections and the metal film while the resistance meter detects an electrical resistance of the metal film and until the detected electrical resistance reaches a predetermined value such that a top surface of the first projection has a specified size and becomes flush with a surface of the second projection providing the air bearing surface.

8. A method according to claim 7 ; wherein in the polishing step, a top surface of the polished metal film becomes flush with the top surface of the polished first projection and the surface of the polished second projection.

9. A method according to claim 7 ; further comprising the step of arranging a flat polishing material so as to confront the surface of the substrate; and wherein the polishing step comprises polishing the first and second projections using the flat polishing material.

10. A method according to claim 7 ; wherein the step of forming the metal film comprises the steps of depositing a sacrificial layer on another surface of the first projection, depositing the metal film on the at least one surface of the projection, and removing the sacrificial layer deposited on the another surface of the first projection.